void selftest_client_xmit_packet(struct Adapter *adapter, struct Thread *thread, struct Packet *pkt)
{
struct TestAdapter *testadapter = (struct TestAdapter *)adapter->userdata;
struct TestAdapter *other;
struct Selftest *selftest = testadapter->parent;
struct Frame frame[1];
if (&selftest->client == testadapter)
other = &selftest->server;
else
other = &selftest->client;
{
struct PcapFile *x;
x = pcapfile_openwrite("self-query.pcap", 1);
pcapfile_writeframe(x, pkt->buf, pkt->max, pkt->max, 0, 0);
pcapfile_close(x);
}
network_receive(
frame,
thread,
other->adapter,
0,
0,
pkt->buf,
pkt->max);
}
/****************************************************************************
* During a self-test, we intercept the client "transmit" function to
* instead forward directly to the server "receive" path, thus simulating
* from the server's point of a view the reception of a packet. We also
* intercept the reverse path in the function
* "selftest_server_to_client_response".
****************************************************************************/
void
selftest_client_to_server_query(struct Adapter *adapter,
struct Thread *thread, struct Packet *pkt)
{
struct TestAdapter *testadapter = (struct TestAdapter *)adapter->userdata;
struct TestAdapter *other;
struct Selftest *selftest = testadapter->parent;
struct Frame frame[1];
if (&selftest->client == testadapter)
other = &selftest->server;
else
other = &selftest->client;
/* Save the query packet to a file for inspection */
{
struct PcapFile *x;
x = pcapfile_openwrite("self-query.pcap", 1);
pcapfile_writeframe(x, pkt->buf, pkt->max, pkt->max, 0, 0);
pcapfile_close(x);
}
/*
* SHORT CIRCUIT
* This is supposed to be a "transmit" function from the DNS client,
* but what we are doing instead is just forwarding it to the
* "receive" function of the DNS server.
*/
network_receive(
frame,
thread,
other->adapter,
0,
0,
pkt->buf,
pkt->max);
}
/***************************************************************************
*
* Asynchronous receive thread
*
* The transmit and receive threads run independently of each other. There
* is no record what was transmitted. Instead, the transmit thread sets a
* "SYN-cookie" in transmitted packets, which the receive thread will then
* use to match up requests with responses.
***************************************************************************/
static void
receive_thread(void *v)
{
struct ThreadPair *parms = (struct ThreadPair *)v;
const struct Masscan *masscan = parms->masscan;
struct Output *out;
struct DedupTable *dedup;
struct PcapFile *pcapfile = NULL;
struct TCP_ConnectionTable *tcpcon = 0;
LOG(1, "recv: start receive thread #%u\n", parms->nic_index);
/* Lock this thread to a CPU. Transmit threads are on even CPUs,
* receive threads on odd CPUs */
if (pixie_cpu_get_count() > 1) {
unsigned cpu_count = pixie_cpu_get_count();
unsigned cpu = parms->nic_index * 2 + 1;
while (cpu >= cpu_count) {
cpu -= cpu_count;
cpu++;
}
pixie_cpu_set_affinity(cpu);
}
/*
* If configured, open a --pcap file for saving raw packets. This is
* so that we can debug scans, but also so that we can look at the
* strange things people send us. Note that we don't record transmitted
* packets, just the packets we've received.
*/
/*if (masscan->pcap_filename[0])
pcapfile = pcapfile_openwrite(masscan->pcap_filename, 1);*/
/*
* Open output. This is where results are reported when saving
* the --output-format to the --output-filename
*/
out = output_create(masscan);
/*
* Create deduplication table. This is so when somebody sends us
* multiple responses, we only record the first one.
*/
dedup = dedup_create();
/*
* Create a TCP connection table for interacting with live
* connections when doing --banners
*/
if (masscan->is_banners) {
tcpcon = tcpcon_create_table(
(size_t)((masscan->max_rate/5) / masscan->nic_count),
parms->transmit_queue,
parms->packet_buffers,
&parms->tmplset->pkts[Proto_TCP],
output_report_banner,
out,
masscan->tcb.timeout
);
}
if (masscan->is_offline) {
while (!control_c_pressed_again)
pixie_usleep(10000);
parms->done_receiving = 1;
return;
}
/*
* Receive packets. This is where we catch any responses and print
* them to the terminal.
*/
LOG(1, "begin receive thread\n");
while (!control_c_pressed_again) {
int status;
unsigned length;
unsigned secs;
unsigned usecs;
const unsigned char *px;
int err;
unsigned x;
struct PreprocessedInfo parsed;
unsigned ip_me;
unsigned ip_them;
unsigned seqno_them;
unsigned seqno_me;
/*
* RECIEVE
*
* This is the boring part of actually receiving a packet
*/
err = rawsock_recv_packet(
parms->adapter,
&length,
&secs,
&usecs,
&px);
if (err != 0)
continue;
/*
* Do any TCP event timeouts based on the current timestamp from
* the packet. For example, if the connection has been open for
* around 10 seconds, we'll close the connection. (--banners)
*/
if (tcpcon) {
tcpcon_timeouts(tcpcon, secs, usecs);
}
if (length > 1514)
continue;
/*
* "Preprocess" the response packet. This means to go through and
* figure out where the TCP/IP headers are and the locations of
* some fields, like IP address and port numbers.
*/
x = preprocess_frame(px, length, 1, &parsed);
if (!x)
continue; /* corrupt packet */
ip_me = parsed.ip_dst[0]<<24 | parsed.ip_dst[1]<<16
| parsed.ip_dst[2]<< 8 | parsed.ip_dst[3]<<0;
ip_them = parsed.ip_src[0]<<24 | parsed.ip_src[1]<<16
| parsed.ip_src[2]<< 8 | parsed.ip_src[3]<<0;
seqno_them = TCP_SEQNO(px, parsed.transport_offset);
seqno_me = TCP_ACKNO(px, parsed.transport_offset);
/* verify: my IP address */
if (parms->adapter_ip != ip_me)
continue;
/*
* Handle non-TCP protocols
*/
switch (parsed.found) {
case FOUND_ARP:
/* OOPS: handle arp instead. Since we may completely bypass the TCP/IP
* stack, we may have to handle ARPs ourself, or the router will
* lose track of us. */
LOGip(2, ip_them, 0, "-> ARP [%u] \n", px[parsed.found_offset]);
arp_response( parms->adapter_ip,
parms->adapter_mac,
px, length,
parms->packet_buffers,
parms->transmit_queue);
continue;
case FOUND_UDP:
case FOUND_DNS:
if (!is_my_port(masscan, parsed.port_dst))
continue;
handle_udp(out, px, length, &parsed);
continue;
case FOUND_ICMP:
handle_icmp(out, px, length, &parsed);
continue;
case FOUND_TCP:
/* fall down to below */
break;
default:
continue;
}
/* verify: my port number */
if (parms->adapter_port != parsed.port_dst)
continue;
/* Save raw packet in --pcap file */
if (pcapfile) {
pcapfile_writeframe(
pcapfile,
px,
length,
length,
secs,
usecs);
}
{
char buf[64];
LOGip(5, ip_them, parsed.port_src, "-> TCP ackno=0x%08x flags=0x%02x(%s)\n",
seqno_me,
TCP_FLAGS(px, parsed.transport_offset),
reason_string(TCP_FLAGS(px, parsed.transport_offset), buf, sizeof(buf)));
}
/* If recording --banners, create a new "TCP Control Block (TCB)" */
if (tcpcon) {
struct TCP_Control_Block *tcb;
/* does a TCB already exist for this connection? */
tcb = tcpcon_lookup_tcb(tcpcon,
ip_me, ip_them,
parsed.port_dst, parsed.port_src);
if (TCP_IS_SYNACK(px, parsed.transport_offset)) {
if (syn_hash(ip_them, parsed.port_src) != seqno_me - 1) {
LOG(2, "%u.%u.%u.%u - bad cookie: ackno=0x%08x expected=0x%08x\n",
(ip_them>>24)&0xff, (ip_them>>16)&0xff, (ip_them>>8)&0xff, (ip_them>>0)&0xff,
seqno_me-1, syn_hash(ip_them, parsed.port_src));
continue;
}
if (tcb == NULL) {
tcb = tcpcon_create_tcb(tcpcon,
ip_me, ip_them,
parsed.port_dst,
parsed.port_src,
seqno_me, seqno_them+1);
}
tcpcon_handle(tcpcon, tcb, TCP_WHAT_SYNACK,
0, 0, secs, usecs, seqno_them+1);
} else if (tcb) {
/* If this is an ACK, then handle that first */
if (TCP_IS_ACK(px, parsed.transport_offset)) {
tcpcon_handle(tcpcon, tcb, TCP_WHAT_ACK,
0, seqno_me, secs, usecs, seqno_them);
}
/* If this contains payload, handle that */
if (parsed.app_length) {
tcpcon_handle(tcpcon, tcb, TCP_WHAT_DATA,
px + parsed.app_offset, parsed.app_length,
secs, usecs, seqno_them);
}
/* If this is a FIN, handle that. Note that ACK +
* payload + FIN can come together */
if (TCP_IS_FIN(px, parsed.transport_offset)
&& !TCP_IS_RST(px, parsed.transport_offset)) {
tcpcon_handle(tcpcon, tcb, TCP_WHAT_FIN,
0, 0, secs, usecs, seqno_them);
}
/* If this is a RST, then we'll be closing the connection */
if (TCP_IS_RST(px, parsed.transport_offset)) {
tcpcon_handle(tcpcon, tcb, TCP_WHAT_RST,
0, 0, secs, usecs, seqno_them);
}
} else if (TCP_IS_FIN(px, parsed.transport_offset)) {
/*
* NO TCB!
* This happens when we've sent a FIN, deleted our connection,
* but the other side didn't get the packet.
*/
if (!TCP_IS_RST(px, parsed.transport_offset))
tcpcon_send_FIN(
tcpcon,
ip_me, ip_them,
parsed.port_dst, parsed.port_src,
seqno_them, seqno_me);
}
}
